Inductor with terminal carrier

ABSTRACT

A COIL WINDING ASSEMBLY COMPRISING A BOBBIN WITH A NUMBER OF TURNS OF WIRE TO FORM A COIL, THE ENDS OF THE WIRE BEING CONNECTED TO MAIN SUPPLY LEADS BY MEANS OF TERMINAL TAGE PROVIDED ON A TERMINAL CARRIER IN THE FORM OF A PLATE SEPARATE FROM THE BOBBIN AND MOUNTED ON THE CORE ADJACENT ONE END FLANGE OF THE BOBBIN. TWO SIMILAR BOBBINS ARE PROVIDEE IN END TO END RELATIONSHIP ON THE CORE, WITH THE TERMINAL CARRIER SANDWICHED THEREBETWEEN.

Jim. 5 1971 N. LANE mbu'cwon WITH TERMINAL CARRIER Filed March 42'. 1969 United States Patent 3,553,621 INDUCTOR WITH TERMINAL CARRIER Norman Lane, Halesowen, Worcester, England, assignor to BSR Limited, Cradley Heath, Warley, England, a British company Filed Mar. 4, 1969, Ser. No. 804,119 Claims priority, application Great Britain, Mar. 9, 1968, 11,619/ 68 Int. Cl. H01f 15/10 US. Cl. 336-192 Claims ABSTRACT OF THE DISCLOSURE A coil winding assembly comprising a bobbin with a number of turns of wire to form a coil, the ends of the wire being connected to main supply leads by means of terminal tags provided on a terminal carrier in the form of a plate separate from the bobbin and mounted on the core adjacent one end flange of the bobbin. Two similar bobbins are provided in end to end relationship on the core, with the terminal carrier sandwiched therebetween.

BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to coil windings for electrical equipment and more particularly relates to relatively low power equipment such as equipment of a domestic nature for example, coil windings for electric motors for use in such things as record players, tape recorders, vacuum cleaners, food mixers and the like.

Further, the invention is concerned with coil windings of the type in which the wire of the coil is wound upon a former, generally termed a bobbin, which expression is used hereinafter, and which bobbin comprises a central tubular part with an outwardly extending flange at each end of the tubular part with the wire being wound upon the tubular part to build up a coil in between the end flanges. Such coil windings will be referred to hereinafter as of the type specified.

(2) Description of the prior art In one method of assembly of coil windings of the type specified, which is widely used at present, the ends of the wire of the coil, which is generally relatively fine wire, are connected to the appropriate leads from the electrical supply, by soldering the appropriate end of the wire to its associated lead and then the soldered joint thus formed is covered with a sleeve of insulating material and to make a compact article the joint so formed is secured to the outer circumference of the coil and held in position by encircling the coil and joint with an adhesive insulating tape. This is a relatively complicated operation which has to be performed manually and takes time and generally adds to the cost of production.

A method of production of coil windings of the type specified is also known in which the end flanges of the bobbin have fixed thereto metal tags and the ends of the wire of the coil can be soldered to these metal tags and also the ends of the leads from the electrical supply can be soldered to the appropriate tags, but this method carries with it certain disadvantages, one of which is that the tags attached to the flanges of the bobbin are likely to be damaged or broken off particularly when the bobbin is in the coil winding machine and rotating at relatively high speed during the actual winding on of the wire to form the coil. Also, it is common practice nowadays to make the bobbins as mouldings in a plastics material and the effect of the heat in the soldering operations to attach the wires and electrical leads to the tags can lead to soften- 3,553,621 Patented Jan. 5, 1971 ing or destruction of the parts of the flanges of the bobbins to which the tags are attached.

SUMMARY OF THE INVENTION A broad object of the present invention is to provide improvements in the means for connecting the wires of the coil to the electric supply leads which will enable the use of such plastics material bobbins as, above referred to, and also the use of winding machines for the formation of the coil but without the previous disadvantages of the method of using tags above referred to.

According to one aspect of the present invention, we provide, in a coil winding assembly comprising a core, a bobbin mounted on said core, said bobbin having a cen tral tubular part and an outwardly extending flange at each end of the tubular part and a plurality of turns of wire around said tubular part between said end flanges, the improvement comprising a terminal carrier mounted on said core adjacent one of said end flanges and terminal tags carried by said terminal carrier for connection to said coil and to electric supply leads.

The terminal carrier may be made of electrically insulating material which is heat resistant.

The terminal carrier may be in the form of a plate adapted to be mounted in face to face relationship with said end flange.

A more specific aspect of the invention relates to the particular case of a coil Winding assembly in which two separate coils are wound on a composite bobbin. An example of this application is that of an electric motor for a record player having two field windings where one coil is provided with an over-winding to act as the secondary of a transformer the field coil winding associated with the over-winding acting as the primary of the transformer and the output from the secondary coil being used tosupply power for an amplifier embodied in the record player.

As at present produced, such a composite bobbin is made as a one-piece bobbin having a central outwardly extending flange in between the two end flanges so as to provide, in effect, two bobbins, in one with the two field coils being wound upon the two halves of the bobbin. With the method of connecting the ends of the coil wires to their associated leads, as above referred to, this method of production of a composite bobbin is furthercomplicated by the addition of the extra lead carrying the power from the secondary of the transformer and the additional operations required for connecting these leads to the end of the wire on the secondary coil winding.

Thus, according to another aspect of the invention, we provide a coil winding assembly as specified hereinbefore, wherein a second bobbin comprising a central tubular part and an outwardly extending flange at each end of the tubular part and a plurality of turns of wire around said tubular part between said end flanges, is mounted on said core on the opposite side of said terminal carrier to said first mentioned bobbin.

In the particular case of an electric motor for a record player and in order to comply with a current standard for the inclusion of a fuse in the circuit, the present invention is particularly advantageous in that the necessary fuse can be conveniently embodied in and carried by the terminal plate with appropriate tags being provided on the terminal plate for connection of the fuse into the electrical circuit.

BRIEF DESCRIPTION OF THE DRAWINGS Two embodiments of the invention will now be described in more detail by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of a coil winding assembly according to the invention,

FIG. 2 is a front elevation of the terminal plate of one embodiment of the invention, and

FIG. 3 is a front elevation of the terminal plate of a second embodiment of the invention.

DESCRIPTION OF PREFERRED EMBODIMENT In both embodiments described herein a coil winding assembly for an electric motor for a record player is described. The electric motor is of the type having two field windings. If desired one of the windings of the motor may be provided with an over-winding to act as the secondary of a transformer for supplying power to an amplifier associated with or embodied in the record player.

Thus, the motor has two coil windings, shown in FlG. 1, comprised by two separate bobbins of similar form and 11, each bobbin comprising a central tubular part 12 which can receive a core of the motor and an end flange 13 at each end of generally rectangular form. Each bobbin 10, 11 is made as a moulding in a suitable plastics material. The bobbin has a coil of wire wound around the part 12 between the flanges 13 to provide the coil windings 14, 15. When assembled in the motor or ready for insertion in the motor, the two bobbins 10, 11 with the coil windings 14, 15 thereon are located in axially aligned relationship with the opposed end flanges 13 in face to face relationship and the end flanges 13 of the separate bobbins are provided at appropriate positions with suitable apertures, not shown, through which the ends of the wires of the coils 14, 15 can pass for subsequent connection to a centrally disposed terminal plate 18 hereinafter to be described in detail.

The coils 14, 15 of wire on each bobbin 10, 11 are wound in the usual manner on the appropriate winding machine and an outer covering of insulating tape 17 applied leaving the ends of the wire of the coils projecting for passing through the apertures, not shown, and subsequent attachment to the terminal tags of the centrally disposed terminal plate 18.

The terminal plate 18 is a flat plate of generally rectangular form, formed of a suitable electrical insulating material, also having such properties that it is not damaged by the heat of subsequent soldering operations to be performed to secure the wires and mains leads to the tags. A material such as bakelised paper or a mica material may be used or any other suitable material having the above mentioned properties.

Electric motors of the type under discussion for use in record players may require a fuse incorporated in the electric circuit thereto in order to comply with an existing standard. The terminal plate may therefore take one of two forms, depending upon the type of fuse which it is desired to incorporate.

The fuse may be embodied as an integral part of the terminal plate or the fuse may be of a type which is a separate and detachable fuse which can be replaced when required. In addition, in certain circumstances it may not be necessary to provide any fuse at all. In the first embodiment to be described the terminal plate may either be provided with no fuse at all or may be provided with a fuse permanently mounted thereon. Referring particularly to FIG. 2, the terminal plate 18 is of generally rectangular form and has a generally rectangular substantially central opening 19 of a form to correspond to the shape of the pack of laminations of the core of the electric motor, not shown, about which the bobbins and the terminal plate will be placed in the final assembly.

Considering one edge 20 of the terminal plate as being the inner edge, the aforesaid opening 19 is disposed nearer to the inner edge 20 than to the outer edge 21 and the dimension of the terminal plate, between these inner and outer edges, is slightly greater than the corresponding dimension of the flanges 13 of the bobbins 10 and 11 so that when the terminal plate 18 is assembled in between the opposed flanges 13 of the two bobbins 10, 11 this outer edge 21 projects outwardly beyond the edges of the two bobbin flanges at the back of the motor assembly.

Adjacent the outer edge 21 the terminal plate is provided with four spaced apart apertures in which are fixed terminal tags 24:: and 24b, of generally known form, and along one side edge 25, in this case close to the inner edge of the terminal plate, there are provided two further apertures which are fixed to further tags 26.

Each terminal tag 24a, 24b and 26 is made as a metal pressing and comprises a central rivet portion with two arms 27 extending radially outwardly on opposite sides of the central rivet portion. The rivet portion of the tag is inserted through its appropriate aperture in the terminal plate and then riveted over to secure it firmly in position and located so that one arm 27 of the tag extends outwardly away from the. edge 21 or 25 of the terminal plate and the other arm extends inwardly along the face of the terminal plate.

A mains lead 28 and one end 29 of the wire of one coil winding 14 are secured to the outwardly projecting arm 27 of the outermost tag 24a. The other end 30 of the winding 14 and one end of a connecting wire 31 are soldered to the outwardly projecting arm 27 of the other tag 24a. The other end of the connecting wire 31 and one end 32 of the other coil 15 are soldered to the outwardly projecting arm 27 of the innermost tag 24b. The other end 33 of the coil 15 and another mains lead 34 are soldered to the outwardly projecting arm 27 of the outermost tag 24b. If desired, a fuse may be connected in series with the coil by soldering the ends of the fuse to appropriate inwardly projecting arms of the tags.

Any known form of suitable fuse may be used between the two terminal tags provided for the reception of the fuse such as, for example, a piece of low melting point fuse wire or, there may be provided a wire coiled to form a torsion spring with one of its ends soldered to one of the terminal tags by a low melting point solder and the arrangement being such that in the event of over-load the solder will melt to allow this end of the coil fuse to spring away from the terminal tag under the influence of the spring and thus break the electrical connection.

The fuse may be provided in an aperture provided in the terminal plate.

If an over-winding is provided for one of the coils 14 or 15 the ends of the coil are connected to the tags 26 as are the leads to the amplifier.

The terminal plate 18, as above described, is then located between the opposed flanges 13 of the two bobbins 14, 15 and the faces of these opposed flanges are recessed slightly at appropriate positions so as to accommodate the projecting portions of the tag 24a and 24b on the terminal plate 18, so that in the final assembly the terminal plate 18 is sandwiched between the opposed flanges 13 in a tight, compact, assembly. The terminal plate 18 is supported upon the core, not shown, of the electromagnet thus firmly securing the plate to the motor so that no strain is imposed on the bobbins.

Thereafter, the final operation of soldering the ends of the wires of the coils to the appropriate tags and the soldering of the electrical supply leads and the supply leads to the amplifier from the secondary coil can be carried out as a simple series of operations without interfering in any way with the complete assembly of the two bobbins.

In a second embodiment of the invention the coil winding assembly is provided with a detachable type of fuse. Referring now particularly to FIG. 3, the coil winding assembly is substantially as described hereinbefore except for the features now to be described. In this embodiment instead of four tags 24a and 24b only three are provided one of the tags 24b being omitted. In addition, a slot 40 is formed in the terminal plate 18 and extending inwardly from the outer edge 21 thereof. The slot 40 is adapted to receive a detachable fuse in sliding engagement therewith. The fuse is of conventional form and comprises two wires 35, 36 secured together at one end by a low melting point solder and separated a ong their length by a strip of plastics material which forms the shank of a T shaped holder 41 the head of which is engaged in the slot 40. In this embodiment one mains lead 28 and the one end 29 of the coil winding 14 are soldered to the outermost tag 24a whilst the other end 30 of the winding 14 and the end 32 of the winding 15 are soldered to the other tag 24a. The other end 33 of the coil 15 is soldered to one end of one wire 35 of the fuse whilst the other wire 36 of the fuse is connected to a connecting wire 37 which is soldered to the tag 24b as is the other mains lead 34.

It will be appreciated that the precise number and arrangement of tags can be varied to suit the circumstances of use. For example, the coils 14 and 15 could be connected in parallel if desired.

The invention therefore provides a means of eliminating the operation of having to solder the ends of the Wires of the coils to the appropriate leads and the taping of these wires under the covering tape around the coils, and thus provides the advantages of terminal tags but as the tags are on the terminal plate which is of a special material and form there is no possibility of damage to the tags as the plate is itself slipped into the final assembly and the tags are in no way involved in the rotation of the bobbins during winding operations. Furthermore, the soldering of the wires and leads to the tags is rendered easier and there is no possibility of damage being caused to the flanges of the bobbins from the heat of the soldering operations.

Furthermore, the invention provides the additional advantage of being able to incorporate means for a detachable fuse or a built-in fuse in the terminal plate.

What I claim then is:

1. In a coil winding assembly comprising a core, a bobbin having a central tubular part and an outwardly extending flange at each end of the tubular part and a plurality of turns of Wire around the tubular part between said end flanges, said core being positioned within said tubular part to mount the body on the core, the improvement comprising a terminal carrier, formed separately from said core and said bobbin and mounted on said core adjacent one of said end flanges of the bobbin and terminal tags carried by said terminal carrier for connection to said coil and to electric supply leads.

2. A coil winding assembly according to claim 1, wherein the terminal carrier is in the form of a plate and is mounted in face to face relationship with said end flange.

3. A coil winding assembly according to claim 1 wherein said terminal carrier is made of an electrically insulating material Which is heat resistant.

4. A coil wind assembly according to claim 1, wherein said terminal carrier has at least two apertures formed therein to receive and mount terminal tags thereon.

5. A coil winding assembly according to claim 1, wherein the terminal carrier is provided with means to mount a fuse thereon.

6. A coil winding assembly according to claim 1 Wherein the terminal carrier is of generally rectangular laminar configuration.

7. A coil winding assembly according to claim 1, wherein the terminal carrier has an aperture formed therein within which is received the core to mount the terminal carrier thereon.

8. A coil winding assembly according to claim 1, wherein the terminal tags of the terminal carrier project outwardly from an edge of the terminal carrier.

9. A coil winding assembly according to claim 1, wherein a second bobbin comprising a central tubular part and an outwardly extendingflange at each end of the tubular part and a plurality of turns of Wire around said tubular part between said end flanges, is mounted on said core on the opposite side of said terminal carrier to said first mentioned bobbin.

10. A coil winding assembly according to claim 9 wherein at least one of the coil windings is provided with an over-winding and said terminal carrier is provided with terminal tags for connection to said over-wind- 111g.

References Cited UNITED STATES PATENTS 326,270 8/1885 Burnley 336192X 840,531 1/1907 Walsh 336-192 2,782,283 2/1957 Schwennesen 3 l715X 3,131,371 4/1964 Brekke 336192 3,389,302 6/1968 Miller 317-15 ELLIOT A. GOLDBERG, Primary Examiner U.S. Cl. X.R. 317-15 

